Tangential cylinder valve



D. G. DEBO 3 Sheets-Sheet l illlllillllilllll/l FEZ March 4, 1952 TANGENTIAL vCYLINDER VALVE:

Filed NOV. 29, 1947 March 4, 1952 D G, DEBO 2,587,704.

TANGENTIAL CYLINDER VALVE Filed Nov. 29, 1947 3 Sheets-Sheet 2 A l Y i u i L l\ R l INVENTOR.

De/mer G. Debo BY TORNEY March 4, 1952 D. G. DEBO TANGENTIAL CYLINDER VALVE 3 Sheets-Sheet 3 Filed Nov. 29, 1947 w w lllylllllyll :11n/lli? I I l I I I l. lllllll l\` I INVENTOR. De/mer G Debo BY l 4 ATORNEY' Patented Mar. 4, 1952 TANGENTIAL CYLINDER VALVE Delmer G. Debo, Chicago, Ill., assignor to Standard. Cil Company, Chicago, Ill., a corporation of Indiana Application November 29, 1947, Serial No. 788,849

7 Claims.

This invention relates to an improved valve and it pertains more particularly to a valve structure for throttling the flow of fluids containing suspended abrasive solids.

In processes for handling iinely divided abrasive solids in uid suspension a serious erosion problem is presented when it is necessary to throttle the flow of the fluid, particularly when it is desired to throttle to a lowe'' pressure while maintaining a substantially constant back pressure. Such a problem is presented, for example, in the throttling of the flue gases containing entrained catalyst particles from the top of a regenerator in a iiuid type catalytic cracking system. In auid catalytic cracking system designed to process about 20,000 barrels per day of gas oil charging stock and employing a synthetic silica alumina, silica magnesia or claytype catalyst ofv small particle site,l the catalyst is transferred from*y a low pointI in the reactor to the regenerator and from a low point in the regenerator back to the reactor by utilizing the static headl of iuidized catalyst in standpipes supplemented by the pressure above the standpipe inlet to obtain thev pressurey differential required y for effecting such transfer. Since the pressure dierential for obtaining solids transfer is dependent inpart on the pressure above the* standpipe it is desirable to maintain a substantially constant pressurein the upper partfof the reactor and regenerator respectively.

The regeneration gases after passing through a number of cyclone separators are discharged from the top ofthe regenerator vessel through a pipe about 6 feet inl diameter which may discharge tothe atmosphere. The amount of lue gasand-steam thus vented to the atmosphere may be of the orderof 290,000 to 390,000 pounds per hour and the entrained solids in said gases may amount to about Souto-600 pounds or more'per hour. The gasvelocity in the regenerated iiue gas outlet pipe may-thus be of theA order of about lOilfeet` per second. An object of my invention istoprovide a throttling valve for said regenerator outlet pipe which will withstand the-severe erosion conditions for a long period of timeand which will eiectively maintain a` substantially constant back pressure in the regenerator. A further object is to providea valve whose'eflectiveness is not destroyed by severel erosion and which can be used for a muchlonger period of time without repair or replacement` than. any otherv valve heretofore known to the art. rPhe repair or repl'acen'ientl of such a valve requires that the entire catalytic cracking unit be shut down and this involves enormous expense and loss of production aswell as the expense-of the valve mechanismper se. An important object ofthe invention is to lproduce a-valve .which .will withstand the severe abrasion and erosion to such outlet pipe.

an extent that the cracking unit will not have to be shut down for repair or replacement' of said valve.

A further object of the invention is to provide a method and means for deadening or eliminating the noise of venting flue gases from a regenerator Such noise is apparently generated by the passage of gases at high velocity over relatively sharp surfaces andthe noise from a regenerator outlet in a 20,000 barrel per day cracking unit has constituted a serious problem. Many methods have been employed to eliminate this noise but heretofore they have been unsuccessful.

A further object is to provide improved methods and means for installing. valves so that they are readily accessible for repair or replacement and so that such repair or replacement may be eiected with a minimum of time and effort.

While the invention is prirnarly directed toward the solution of a serious problem in connection with the venting of flue gases from catalytic cracking regenerators, an object of the invention is to provide a type of valve structure which will be generally useful for throttling or controlling the flow of fluids particularly when said fluids contain erosive solids. Other objects Will be apparent from. the following description The valve structure of the present invention may be briefly characterized as a pair of rotatable segmented cylinders mounted to rotate on parallel axes spaced from each other so that the segmented portions of the cylinders Will form an opening therebetween when the cylinders are in one position and so that said opening maybe controlled and/or closed by rotating the cylinders to another positioin-the back side and ends of the cylinders being constantly sealed in all operative positions ofthe rotatable cylinders. As the Huid enters and passes through the opening between the segmented cylinders the high velocity stream does not pass over any sharp edges and thus both erosion and noise are minimized. The severest erosion usually takes place on the upstream lower) side ofthe valve although some erosion of course takes place in the valve throat and on the downstream side. When a portion of the cylindrical surfaces becomes eroded, the cylinders may simply be rotated a little further to present fresh surfaces and to provide an opening of substantially the same cross sectional area regardless of erosion. By making the valve surfaces of a hard metal such as carbon steel or hard metal alloy and by providing increased thickness in the cylinder walls which are subjected to severest erosion, a relatively light weight valve of ertremely long life may be produced. The valve may be employed as a shutoff` valve by rotating the cylindersvuntil the unsegmented portionsbear against each other. By mounting the shafts which support the cylinders on antifriction supports and providing a link-lever system for simultaneously rotating the cylinders in opposite directions, the pressure drop through the valve may be controlled with great ease and precision and a substantially constant back pressure may be maintained on the upstream side.

The invention will be more clearly understood from the following detailed description of a speoic example thereof read in conjunction with the accompanying drawings which form a part of this specification wherein similar parts are designated by like reference characters in several views and wherein:

Figure 1 is a schematic vertical section through a regenerator flue gas outlet pipe illustrating the position and operation of the valve structure;

Figure 2 is a schematic detail illustrating the valve in wide open position;

Figure 3 is a similar schematic detail illustrating the valve in normal operating position;

Figure 4 is a schematic detail illustrating the valve in ultimate closed position;

Figure 5 is a vertical section of the valve struc ture taken along the lines 5 5 of Figure l;

Figure 6 is a horizontal section taken along the lines 5-5 of Figure 1;

Figure 7 is transverse cross-section of one of the segmented cylinders;

Figure 8 is a horizontal section through one of the segmented cylinders; and

Figure 9 is a detail of the bearing arrangement taken along lines 9-9 of Figure 5.

The invention will be described in connection with the venting of flue gas from the regenerator outlet in a 20,000 barrel per day fluid type catalytic cracking plant but it should be understood that such description is by way of example and that the invention is applicable generally to the control of fluid flow and particularly to the throttling of fluids which contain erosive solids suspended therein. The fluid catalytic cracking regenerator vessel may be about 37 feet in diameter and about Ll0 feet in height.

In the upper part of the vessel there are usually several stages of cyclone separation, the cyclones of the last stage discharging gases into a walled-onf portion at the top of the vessel. A pipe section II is secured to the top of regenerator vessel I2. At the base of pipe section I! a perforated distributor plate I3 is interposed which plate may be about two inches thick and which is provided with a multitude of holes I4 about one inch in diameter spaced at two or three inches centers and rounded on the lower edges. The purpose of this perforated plate is to provide a pressure drop of approximately 1 p. s. i., to provide even distribution across the entire crosssectional area of the upflowing stream toward the valve inlet and to avoid erosion of the vesseland/or pipe at this point in the system. 1f e.'

desired, replaceable ferrules, i. e. short pipe sections about one inch in diameter and four or five inches long may be used instead of simple holes.

A 3-inch base plate 5 is secured between the upper flanged ends of pipe section II and the lower flanged ends of pipe section I5. Base plate I5 is provided with a rectangular central opening Il which may be about 24 inches wide and about 48 inches long, the inner edges of the plate being rounded particularly along the Llil-inch side of the opening. Arcuate shaped steel plates It about l inch in thickness are welded to the upper side of base plate I5 along the 48-inch sides of opening I'I, to form seals for valve rotors or cylinders I9 and 20 as will hereinafter be described.

Inclined steel plates 2I are welded to the upper part (about l inch below the top) of arcuate plates i8 and they extend upwardly at an angle of about 60 degrees to the outer walls of pipe I6. Vertical steel plates 22 are welded to base plate IS and inclined plates 2| to provide necessary strength andv also to provide a chamber which may be sealed with relatively light weight high temperature cement 23 (such as Gunnite, Lumnite, etc.) prepared from a light weight refractory material such as kieselguhr or Alundum ad- Inixed with a mortar which, on setting, will withstand high temperatures of the order of 1000D F. The same type of refractory cement may be sprayed or otherwise applied on the inner sides of pipe sections I l, I6, etc. and on the upper side of inclined plate 2l and the corresponding inclined plates at the ends of rotors is and 2i), such high temperature cement or mortar being smoothed on to provide rounded surfaces for minimizing noise and erosive wear. rThe high temperature cement in the space between arcuate member I8 and plate 22 adds additional protection since it avoids the necessity of shutdown for repair even though a hole be eroded through plate 2l immediately above the valve. The high temperature cement has a sound adsorhing or deadening effect in addition to its function of protecting metal surfaces against erosion.

About two or three pipe diameters above base plate l5 another plate 24 is interposed, this plate containing a multitude of openings (like open ings Ill) or replaceable ferrules 25 of about the same size and spacing as openings lil in plate I 3. Still further plates with openings or ferrules may be employed is still higher parts of the regenerator outlet pipe for minimizing the amount of pressure drop which must be taken across the valve itself.

Rotatably mounted above opening I1 in base plate I5 are rotors which may be described as deformed, segmented or flattened cylinders I9 and 20, the specific structure of which is illustrated in Figures 7 and 8. To minimize weight and material these rotors or deformed cylinders are preferably hollow castings of hard metal such as carbon steel or a har-d metal alloy of iron, nickel, chromium, molybdenum, tungsten, silicon, etc. with small amounts of carbon. In this specific example the deformed cylinders are 18 inches in outside diameter and 42 inches long, the hollow section extending to within about 9 inches of each end. The hollow section may be about 131/2 inches in diameter, the center about 3A inch higher than the center of the cylinders so that the thickness of the cylinder at the top will be 'about 11/2 inch' and the thickness atY the bottom.

will be about 3 inches. The cylinder is deformed or segmented by having a flattened surface 25 about 5 inches .from the center of the cylinder, the wall thickness of this side of the hollow cylinder being about 2 inches. The ends of the 1f: cylinder are provided with central openings 2l about Ll1/2 inches in diameter. If desired, a pipe Yof noncorrosive metal may extend throughout the vlength of the cylinder said pipe fitting snugly in openings 2l and having an internal diameter of about 4 inches so that it may be easily slid onto and off of a supporting shaft. When such a pipe extends throughout the length of the cylinder the hollow space between the pipe and the cylinder walls may be filled with light weight high temperature cement.

While surfacev 2'6z on. the rotor or' deformed cylinder Ais `ini a;rsingleplane`l` in the'l example herein described;v it' should be understood that 'the exipressicn- "flattenedrcylinder is intended to mean any deformation of.` the cylinder Vby havingf at least one side thereof'clos'e'r' to the center than other sidesthereof.v 'In other wordsVfa'ce 26 kmay be slightly' convex but less thanv 9` in'ch'eslfrom 'the center.l 'The cylinder may 'of co'urse'lcesolidi` and one `side'. 'thereof be cutaway.- If.. the cylinders are-mounted further apart' than thesuml of their radii, the deformed portion may'actually protrude outwardly. Any such deviation from a` true cylindrical/surface ifs herein referred to by eX- pressions suchias' deformed and. flattened and when at thepcint ofdeforma'tion the surface-is closer to the' center than the 'main cylinder wall, theexpression segmented is intended to-have the samesigniflcance as ilattenedf 7' The structural mounting. ofthe. rotors or deformed cylinders is mostV clearly illustrated in Figure 5. A 4-inch alloy steel shaft 28' extends through openings2=9 and 30 ini the `G-foot internal diameter pipe section I6, each opening beingprovided-with a packing. gland 3I and a grease connection 32 for introducing: lubricant into the packing material. Vertical plates 33 are welded to b'aseplate I6 at each'end of the rotors or deformed. cylinders' to provide ar seal therefor and inclined'plates 34' extend. at an angle of about 6D degrees from the upper part of. plates I3 to the walls of pipe I'I, plates 34 corresponding to plates Z'Ii'andcooper'ating therewith to form a hopper- Yshaped path for uids discharged from the valve. Platesf34" like platesv 2l maybe provided with coating of high temperature cement'about' l-i'nch thick. Plate 33 hasopenings'and136'fnr'shaft 28T-and pipe section 31 may befinterp'osed between openings 29 an'd35v and. 3!) and'` 35 respectively with bleed connections 3B- fcr introducing steam or other gasI atscme'what higher pressureithan the ilue gases. This bleed gas introductionis vfor the purposev4 of preventing. solids from entering any crevices in the' systeinl andv thus lcoming'in contact with shaft 28".

"The outer ends of shaft 2'8 arel supported by antifri'ction elements carried by brackets 3 9 which may 'be' spaced at 120 degree angles as'illustrated in Figure 9. Each bracket carries a supporting or positioning wheel 4I] which turns on ball-'bearings 4I. A thrust groove' 421` 'may be provided- "at one end of the shaft and the rollers 4.0 atthat endma'yextend into the thrust groove, the positioning of such roller supports on their brackets 39 tending to position the shaft and prevent longitudinal movement thereof,

The rotors or deformed cylinders may be provided with sleeves 43 of noncorrodable metal which may slide vfreely over the shaft and the rotors are mounted by simply holding them in place and sliding the shaftthrough openingsV 36, then through sleeves 43 and thenthroughop'enings 35; and 29; Relative rotation between.l shaft 28,` and the' rotorsor deformed cylinders; mjay be prevented by' keyingjtheshaft to the rotor' or by the use of' set screws or' tapered pins extending through the' rotor or" deformed! cylinder and against or into the shaft. Inl this `particularcase the'shaft centersare about 9: inches above b'ase plate I5 and 9 inchesffrom the center of pipe I6.

In operation the rotors ordeformed, flattened or segmented cylinders are operated by" rotation thereof in opposite directions. Such rotation may be eifected by any conventional driving means operated by manual, mechanical, pneumatic, hy-

dran-lick or electrical devices.. A preferred operating?structurecomprises a pneumatic or'hydraulic system operating throughllinks and levers' as'illustrated in"Figures"2,` 3 and 4. The outer endof shaft 28 iskeyed or otherwise secured to operating lever 44which in this case mayv be about 13%; inches -i'n length and which is pivotally connectedv tc link 45 which is about 30 inches in length. Similarly, the shaft which supports rotor or deformed cylinder 20 is keyed or otherwise secured' to lever 46 which is pivotally connected to link 41, the last-named elements corresponding in length to lever 44 and link 45 respectively. The' lower ends of links 45v and 4'! are pivotally connected tobar 48 whichv is about 32 inches inV length and which in turn is actuated by a hy-A draulically operated piston rod 49. This piston rod may be actuated by a iluid which is directly or indirectly actuated by the fluid pressure in the upper'pa'rtof the regenerator vessel itself whereby any increase in regenerator pressure automatically elevates piston rod 49 thus causing an opening of the valve and any decrease in pressurecauses a lowering thereof to restrict the valve opening. The wide open position of the valve is illustrated in Figure 2 wherein the flattened s'rfaces of theA rotors or deformed cylinders are substantially" parallel to each other to give an opening about S inches by 4 8 inches or3840 square inches. The normal initial position of the valve is illustrated in Figure 3 wherein downward movement of rod 43 has restricted thek opening to about 2 to 4 inches. It will' be noted that in this position the upfiowlng fluid stream does not pass over any sharp edges but, on the contrary, flows smoothly between' rounded surfaces into a zone of gradually expanding cross-sectional area. which tends to` smooth the flow and prevent thehigh turbulence and' eddy currents which might otherwise cause erosion. The smooth flow over rounded surfaces minimizes and in some cases may eliminate the; noiseprcblem. The smooth flow and avoidance of back-lash at the upper part of the valve likewise minimizes erosion. Sgoineerosion however will inevitably take place at the throatopening and thev lower portions of the rotors or defoijn'iedcylinders will be partially Wor'nj' away. TheI increased thickness of the rotors at their lower edges makes provision for such erosion and the` automatic control continues to function insp'iteof said erosion because any increase' in opening s iae tends to decrease the pressurel drop which, in turn, automatically lowers rodlfand causes` rotation of the rotors to such citent afs to` provide theA opening of required sise. AsV more and more of the metal is worn away from` the deformed cylinders the normal operating position of rod 49 and cross-arm 48 is correspondingly lower, the ultimate positioning 'being indicatedfin Figure4 4 wherein the piston rod-"is in its lowest position, the total vertical travelflengththereof being 24 inches. The valve hereinabove described thus continues to function ina satisfactory manner regardless of enormous a no unts`` of erosion so that' this valve will not 'o "e'th'-eA weak spot'fln the catalytic cracking unit and will jlways continuetofunction as long'as the unit is'on stream.

During shut-downs for other purposes the valves maybe inspected :and repaired .orfr'eplaced by'jsirnplyj withdrawing'fshaft 28 and`tl"1e 'corre sponding'shaft through rotorv 2G" and removing thelrotcr'sfeitherjdownwardly through-opening lI'I or upwardly through "the" tdpoff the vent* pipe or stall.

An important feature of the valve structure hereinabove described is a provision of sealing means for the back side and ends of the rotors. Arcuate plates I8 conform to the true cylindrical shape of the back side of the rotors. In order to prevent any binding of the rotors the arcuate plates are usually spaced from the rotors by about to l/r of an inch so that a fluid can actually pass through the sealing space and keep it free from any accumulation of solids. Similarly, end plates 33 are spaced at a like distance from the ends of the rotors of the space between these end plates and the rotors is kept free from solids by a constant flow of bleed gas introduced through connection 38 to the space between pipe 3l and shaft 23. Thus there is no sliding friction between moving metallic parts which is so detrimental in systems for handling nely divided solids.

The seals as hereinabove described and particularly the seals between seal plates I8 and cylindrical surfaces on rotors I9 and 20 are not in this case entirely gas tight but the amount of gas which passes through this seal space is substantially constant and so small in magnitude as to be of no practical importance. The arcuate seal plates i8 should subtend an angle of at least about 60 degrees but less than 180 degrees, the preferable arcuate length being in the range of 90 to 150 or about 120. When the angle between the flattened surfaces is zero, i. e. surfaces are parallel, the width of the opening is 8 inches. When it is about 15 degrees the width is about 4 inches. When it is about 30 degrees the width is only about 1% inches. Thus by increasing the angle between the attened surfaces the opening may be reduced to practically zero, i. e. the cylindrical surfaces contact each other. With extended use the lower part of the valve throat may be somewhat eroded away but the opening can be maintained constant by slight rotation of the cylinders.

While a specific example of the invention has been described in minute detail it should be understoodJ that the invention is not limited to this particular example. When handling finely divided solids in fluids at relatively low temperatures the rotors or deformed cylinders may be of rubber which in some cases is even more resistant to erosion than steel. The materials of construction will be dependent of course upon the type of fluids to be handled and the conditions under which the valve has been designed to operate. In some cases the true cylindrical surface of the rotors may actually bear against the arcuate seal plates and a suitable lubricant may be employed therebetween. In the example hereinabove described, a bleed gas may be introduced at midpoints along the arcuate surface into the seal space between the arcuate bleeds and the cylinders so that such bleed gas will prevent any solids from entering said seal space. Many other modiflcations and alternative structural arrangements will be apparent from the above description to those skilled in the art.

Also other sound-absorbing and/or deadening means may be employed in place of horizontal .perforated plates (exemplified by plate I3) or ferrule assemblies (exemplied by plate 24 and ferrules 25).

Iclaim:

1. A system for throttling the flow of uids lcontaining abrasive solids, which system cornprises a pipe section flanged at one end, a base .plate secured to said angeand provided with a central opening, arcuate plates secured to the upper side of the base plate on each side of the opening, end plates secured to the upper side of the base plate at each end of the opening between the ends of the arcuate plates, an upper pipe section above the base plate, inclined walls leading from the upper parts of the arcuate plates and the end plates respectively to the inner walls of the upper pipe section, a pair of rotatable shafts extending through said end plates, each shaft being concentric with one of said arcuate plates, a rotor keyed to each shaft, each rotor being cylindrical on one side and segmented on another side with its cylindrical portion concentric `with its respective arcuate plateV and spaced at a slight distance therefrom and the ends of each rotor being likewise spaced from the end plates at a slight distance therefrom, a fluid inlet for introducing a sealing uid into the space between the rotor and adjacent metal surfaces and driving mechanism for rotating said shafts in opposite directions so that a substantially constant opening may be maintained between the opposed segmented surfaces of the rotors by rotating said rotors when portions thereof are worn away by erosion.

2. The system of claim l wherein the rotors are hollow with wear resistance walls of varying thickness and wherein the wear resistance walls are thicker at the portion where erosion is encountered than in portions wherein erosion is not encountered.

3. The system of claim 1 which includes a high temperature cement lining on the inner side of the rst named pipe section, on the inclined walls and on the inner side of the upper pipe section above said inclined walls.

4. The system of claim 1 wherein each shaft is provided with a thrust groove for avoiding lateral movement of the rotors and which includes anti-friction bearing supports for each shaft.v

5. The system of claim 1 which'includes a perforated distributor plate in the first named pipe section below said base plate. 6. 'Ihe system of claim 1 which includes an upper plate containing Aa multitude of openings mounted in the upper pipe section above the upper end of said inclined walls.

7. The system of claim 6 wherein replaceable ferrules are mounted in the openings in the upper plate.

' DELMER G. DEBO.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

